A Grapnel Gun is a device which hurls a projectile attached to some sort of rope or line. This line can be used to pull an object closer, to climb a vertical surface in a gravity well, or to move safely and under control toward an object in zero-G. The effectiveness of this device depends on how securely the projectile can be anchored to the target.
A sharp, carbon-alloy projectile is used at TL–8 to TL–13. The head of the projectile embeds itself in the target and immediately releases four perpendicular barbs to hold it in place. Removing the head is a matter of twisting a locking collar to retract the barbs and pulling the head from the surface. This type of projectile uses either a powder or chemical charge with a rope or cable line.
If used as a makeshift weapon it can do a little damage at a very short range and may knock down the target by the grapnel and its trailing rope.
At TL–14, new developments in molecular bonding allow creation of an improved projectile. The projectile head is a polymer/circuitry combination which fastens to any surface. Using a compact, low-voltage power source creates a subatomic electrical bond with the surface it strikes; it, in effect, becomes a part of the target surface. The power level control is at the opposite end of the I braided graphite fiber line and must be set to the proper output for the target surface. Subatomic forces vary with the structure of the atom, and thus different materials require different power level settings. Due to the lighter weight of this projectile and line, the gun is a gauss-type ideal for zero-G use. Therefore, it is highly desired by asteroid mining companies.